Metronomic tempo indicator



June 5, 1 2,555,748

FRIEDRICH WALTER KOENIGSBERGER NOW BY JUDICIAL CHANGE OF NAME WALTERFREDERICK CONINGSBY ETAL METRONONIC TEMPO INDICATOR 2 Sheets-Sheet .1.

Failed May 23, 1945 INVENTORS FRIEDRICH WALTER KOENIGSBERGER, NOW BYJUDICIAL CHANGE OF NAME WALTER FREDERICK OONINGSBY ;AND ANGUS MAC PHAILJune 5, 1951 2,555,748

FRIEDRICH WALTER KOENIGSBERGER NOW BY JUDICIAL CHANGE OF NAME WALTERFREDERICK CONINGSBY ET AL METRONOMIC TEMPO INDICATOR Filed, May 23, 19452 Sheets-Sheet 2 I INVENTORSI FRIEDRICH WALTER KOENIGSBERGER; NOW BYJUDICIAL CHANGE OF NAME WALTER FREDERICK OONINGSBY; AND ANGUS MAOPI'IAIL BY W W Patented June 5, 1951 METRONOMIC TEMPO INDICATORFriedrich Walter Koenigsberger, London, and

Angus MacPhail, Hitchin, England; said Mac- Phail assignor to saidKoenigsberger; said Koenigsberger now by judicial change of name WalterFrederick Coningsby Application May 23, 1945, Serial No. 595,848 InGreat Britain June 1, 1944 3 Claims.

This invention relates to metronomic tempo indicators.

The usual tempo indicator, known as a metronome, consists of anoscillating steel rod Worked by a clockwork mechanism and suspended on apivot with a fixed weight at its lower end and a smaller and movableweight at its upper end, which smaller weight, by being placed near--'er to the pivot, increases the oscillations of the rod per unit period.

The hitherto known metronomes suffer from various disadvantages. Thusthe position of the smaller weight and consequently the rate ofoscillation of the pendulum can be adjusted only while the metronone isstationary. Moreover the clockwork driving mechanism must be wound upperiodically, and finally the indicating signals are of a constantintensity.

One object of the invention is to provide a tempo indicator which canoperate for long periods without interruption.

Another object of the invention is to provide a tempo indicator, theperiodicity of the signals of which is adapted to be varied gradually ormomentarily during the normal operation of the device.

Still a further object of the invention is to provide a tempo indicatorthe intensity of the beats of which is adaptable to the conditions ofthe music, i. e. the sound level of the instrument or instruments, thecharacter of the music and the environmental background.

Still. a further object of the invention is to provide a metronomictempo indicator which is operated electrically instead of mechanically.

Still a further object of the present invention consists in a metronomictempo indicator comprising means for producing an audible or visiblesignal at regular intervals, means for regulating the intensity of saidsignals during the operation of the device" and means by adjusting thetempo of said signals during the normal operation of said device.

Other objects and advantages of the invention will become apparent fromthe following description and claims.

In the drawings, forming part of this specification:

Fig.1 is a diagrammatic representation of one embodiment;

Fig. 2 is a detail of Fig. 1; and

Fig. 3 is a diagrammatic representation of a second embodiment.

In said drawings, like parts are indicated by like reference characters.

In the embodiment shown in Fig. 1, I denotes a synchronous electricmotor driven from a mains circuit A, the shaft 2 of which motor drivesone cone 4 of a twin cone friction gear 4, 5, through a reduction gear3.

The transmission ratio of the cone friction gear 4, 5, is varied by awheel or runner 6 rotatably mounted on a shaft 1 having at its other enda rack 8 engaging a pinion 9 carrying an indicator pointer l0 movingbelow a transparent calibrated dial I I. x

The position of the pointer I0 and thus of the runner 6, is adapted tobe altered by a knob I2 (Fig. 2).

The cone 5 is mounted on a spindle I3 carrying a finger or cam I4 which,during each revolution of the cone, strikes the leaf I5 of a leaf switchI 5, I1, l8, in a mains fed circuit 20 in which is a rectifying circuitcomprising a rectifier 2| (for example a dry plate rectifier). Therectified current from rectifier 2I passes through a resistance 22 viapoints I6, I! of the leaf switch which are normally in contact, tocharge a condenser 23, passing from thence via return lead 24 to themains.

When the cam l4 momentarily depresses the contact I6 into contact withthe contact I8 part of the charge of the condenser 23 is transferred toa sound-producing electrical device 25 of any desired knownconstruction, such as a hammer armature, a loud speaker or the likewhilst another part of the charge of the condenser 23 is transferredthrough a rheostat 26 with movable contact 26a and limiting resistance21, back to the condenser 23.-

In order to prevent the runner 6 being shifted while the cones 4', 5,are stationary and thus imposing unnecessary wear on the mechanism, theknob I2 is operatively connected with the pinion 9 through a magneticclutch comprising a solenoid plate 30 cooperating with a solenoidarmature 3| and engaging same only when the circuit 20 is energised andthe motor I driven.

The circuit of said solenoid comprises a resistance 32 in series withthe coil of 33 of the solenoid plate 30 and shunted by a condenser 34,to ensure smooth action.

The mains circuit also includes a fuse 35 and a main switch 36.-

The apparatus operates as follows:

Onthe mains switch 36 being closed, the motor I rotates while thecircuit 20 is energised, thereby causing the magnetic clutch 30, 3|, toengage. The motor I drives the cam l4 through the cone friction gear 4,5, 6, which periodically actuates may be effected by a knob (not shown)in close proximity to the knob l2 or even coaxial therewith.

The embodiment shown in Fig 3 operates purely electrically and broadlyconsists of an electronic time base circuit.

Said circuit comprises a transformer T, the primary coil 50 of which isfed with A. C. mains current through a fuse 55 and switch 36. Saidtransformer T feeds four secondary windings 52, 53, 54. Winding 5|energises the heater ofa rectifying tube 55, the anodes of which are fedby the secondary winding 52, producing direct current which is smoothedby a condenser 56.

Winding 53 excites the heater of agas discharge triode 51 whilst thewinding 54 energises the heater of a pentode 58.

Rectified current from rectifier 55 charges a condenser 59 through aresistance 60 and pentode 58 whose cathode 58a and third grid 580 aretied and whose anode 58d and second grid 581) are likewise tied. Theanode 5801 is connected to a point 05 in the circuit between resistance60 and a further resistance 6| in series with resistance 60, the tworesistances 60 and BI being shunted across the rectified current supply.A by-pass condenser 62 is further shunted across the resistance 6|. V vi The cathode 58a of the pentode 58 is biassed through the voltage dropproduced by a resistance 63 and a potentiometer 64, the movable contactof which can be operated by a knob 12 which carries a pointer l0traversing a calibrated tempo scale ll illuminated by a pilot lamp 66.

The grid 58c of pentode 58 derives its bias from the negative end of acathode resistance 67.

The gas discharge triode 51 has its cathode 57a tied to point 65 whilethe bias to the grid 51b is fed through a resistance 68 and the anode510 is connected to the primary of a transformer TI and to the condenser59. The secondary winding H of the transformer Tl actuates a loudspeaker or other sounding device 25 the intensity of the signals emittedby which is controlled by a potentiometer 13. a.

The loudspeaker 25 may obviously be replaced by a lamp or other visualsignalling device.

The circuit operates as follows:

On closing the mains switch 36 the primary 50 of transformer T isenergised, thereby simultaneously energising the heaters of tubes 55, 57and 58, tube 55 delivering direct current which charges condenser 59through the constant current charging pentode 58. When the potential ofthe condenser 59 reaches the breakdown point of the gas triode 51, thecondenser is instantly discharged through the primary 19 of transformerTl, the secondary H of which actuates the loudspeaker 25.

From the foregoing description it will be seen that the periodicity ofthe signals emitted by the loudspeaker or other device 25 can be variedby varying the resistance of the potentiometer 64 by means of knob 12while the intensity of the emitted signals can be varied by varying theresistance of the potentiometer 2B.

The metronomic tempo indicator of the present invention is notrestricted for use in the practice of music, but is particularlysuitable for medical treatment, for rehabilitation and for mental orphysical gymnastics.

We claim:

1. In a metronomic tempo indicator an electric circuit including anelectric motor; an in finitely variable cone friction gear including anintermediate runner; said gear being driven by said electric motor; aswitch in said electric circuit; switch closing means driven by saidcone friction gear; a sound emitter in said electric circuit actuated bythe closing of said switch; rack and pinion means for varying theposition of said intermediate runner and thus the transmission ratio ofsaid cone friction gear; a control knob for actuating said pinion; anelectromagnetic clutch connecting the pinion and said control knob; saidclutch being operated from the same circuits as said motor to beenergized simultaneously therewith and a rheostat in said selectriccircuit for varying the intensity of the sound emitted by said soundemitter.

2. In a metronomic tempo indicator a stationarily mounted electricmotor; a first cone having a stationary axis and being driven by saidmotor; a second cone having a stationary axis; a movable intermediaterunner arranged between said cones; said cones and said runner formingpart of a cone friction gear; means for varying the position of saidrunner; a knob; an electromagnetic clutch connecting said knob and saidvarying means; means for energizing said clutch simultaneously with saidmotor; a stationary switch operated by said second cone; a stationarycontact in said switch; and a sound emitting device connected to saidcontact.

3. In a metronomic tempo indicator a stattionarily mounted electricmotor; a first cone having a stationary axis and being driven by saidmotor; a second cone having a stationary axis; a movable intermediaterunner arranged between said cones; said cones and said runner formingpart of a cone friction gear; means for varying the position of saidrunner; a knob; an electromagnetic clutch connecting said knob and saidvarying means; means for energizing said clutch simultaneously with saidmotor; a stationary leaf switch including a movable leaf and beingoperated by said second cone; a stationary contact in said switchadapted to contact periodically said movable leaf; and a sound emittingdevice connected between said contact and said movable leaf.

FRIEDRICH WALTER KOENIGSBERGER.

ANGUS MAoPHAIL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 512,470 Hanson Jan. 9, 18941,769,256 Clarke July 1, 1930 2,045,271 Hopkins June 23, 1936 2,095,213English Oct. 5, 1937 2,184,728 Aalberg Dec. 26, 1939 2,195,255 MyersMar. 26, 1940 2,240,305 Koch Apr. 29, 1941

